Wherefore comfort yourselves together, and edify one another, even as also ye do. - 1 Thessalonians 5:11
IN THIS UPDATE
The Star of Bethlehem???
The Extended Alignment of Jupiter and Venus
Hello Friends,
We have a lot of ground to cover in this newsletter. It was a busy week with the big conjunction, and we heard from a lot of
folks, via email and Facebook. So glad that people were following it! This story actually got a little bump in the mainstream news with this "Star of Bethlehem" business, which we'll discuss below.
Though a lot of people were unfortunately clouded out, a lot of others got to see the
conjunction. But even if you missed the closest night, Jupiter and Venus will remain aligned through the month of July, and this is the neatest, rarest aspect of this event, which you'll never see again. We'll tell you all about it below.
Here's a couple nice excerpts from the emails we received, like this from the McFarland Family:
My six year old is so excited about this (& so are the adults). When we can't go out, we talk about it & she's always mentioning Venus, Jupiter, Castor & Pollux. She tells others about it & they are amazed.
That's really neat
to hear, since childhood is the best time in life to make friends with the stars! Many a famous astronomer was inspired by an early experience with a bright conjunction! But it's never too late to learn the sky, even if you're an adult. Here's an excerpt from Kathleen:
Since discovering your information on classical
astronomy, I feel I have hit the jackpot of practical information, far more practical than the life cycle of a star, which is all I ever got in school.
I had a similar experience myself, being nearly 30 when I began to learn the sky. Before that, I spent a lifetime consuming pop media "big ball astronomy" such as PBS shows about black holes. And yes, most of the available
literature talked about theoretical concepts such as stellar evolution, but never prepared you to simply step outside and observe the sky for yourself. So that's what this newsletter is all about!
Here's an interesting communication from Teresa, in China:
We were in front of the Potala Palace in Lhasa, Tibet, with hundreds of other visitors, pretty much all Chinese from the mainland. One man and his son stopped and talked to us (he knew English), he was Tibetan and we shared watching the planets with him.
Wow, Tibet! Is that cool or what? One amazing thing about the sky is that everyone in the world can see the same sights. The distance between the nations in the world is miniscule compared to the
distances to the planets. Folks were sharing conjunction pictures on Facebook from diverse places such as Brazil, India and Australia, and though there were latitudinal differences, everyone reported a similar sighting.
Family members were communicating with their loved ones in different parts of the
USA, and even in different countries, all while simultaneously observing the conjunction. It was a blessing to share this event long distance, though separated from loved ones. As you'll read below, the blessing of this alignment can go on for another month!
For more information about topics from Classical Astronomy discussed in this newsletter,please check out
a homeschool astronomy curriculum
(but popular with adult readers too!)
Visit our archive of previous editions of the Classical Astronomy Update newsletters, going back to 2007.
Visit this page to subscribe to the Classical Astronomy Update and the Northeast Ohio Astronomy (NEOastro) newsletters.
*****
Star of
Bethlehem???
This 2015 conjunction of Venus and Jupiter did get
picked up in the mainstream media, which was a good thing, since a lot of people were alerted to look for the pair in the evening sky. The downside was, there was an unfortunate spin on this story so that this conjunction was being construed as some sort of recurrence of the Star of Bethlehem.
One of our most common FAQs is "What was the Star of Bethlehem?" The short answer is, if we knew for sure, everyone would already know, and no one would need to ask the question. (The
long answer is explained at this link from our site.) Since there is so much uncertainty, there are always new theories being advanced all the time. Some theories are scholarly, and some, frankly, are pretty kooky. There have been at least two new theories just in 2015 alone, and the year is only half
over!
The latest theory began innocently enough, with a comment in this article in Sky & Telescope:
Sky & Telescope Contributing Editor Fred Schaaf points out that this current trio of Venus-Jupiter conjunctions closely resembles a similar series in 3-2 BC that has been suggested as the Star of Bethlehem. "As has been the case in 2014–15," Schaaf explains, "the first two conjunctions back then were extremely close, the last one
separated by about 1°, all three occurred not far from Regulus, and all were similarly high up in the sky."
In this article, Fred Schaaf refers to a cycle of Venus and Jupiter that occurred in ancient times, which happened to be similar to the current cycle of these planets. But here's an example of how Schaaf's remark got spun in the pop media:
Sky & Telescope suggest that a similar rare conjunction of Venus and Jupiter may have been what was known as the “Star of Bethlehem” in 3-2 BC and since then there has not been a brighter, closer planetary conjunction. That means that this is the first opportunity of seeing it so clear for 2,000 years!
Note closely that Sky & Telescope did not "suggest" any such things! The S&T writers were simply pointing out that the current 2015 cycle of Venus and Jupiter was similar to the one in antiquity. This is just one example of how this report was embroidered and distorted in the media.
The fact is, alignments of Jupiter and Venus are generally quite common, happening every couple years or so. We had an interesting alignment of these same planets in 2012. But a lot of times, the planets are much farther apart at their closest pass, or else they line up too close to the Sun to be readily visible.
The 2015 conjunction was notable for being a very close alignment, and very high in the evening sky, and during June, a month when it's supposed to be warm and clear (even though a strange jet stream this summer caused a lot of observers to be clouded out). This 2015 cycle is especially noteworthy
because of the EXTENDED alignment of these planets, which is very rare, as will be discussed in detail below.
Though this week's conjunction was quite close, there have been other, closer alignments in the last 2000 years. The conjunctions of 3-2 B.C. were indeed extremely close, and occurred in a
similar part of the sky, near the bright star Regulus in the constellation Leo, just like in 2015. Actually, the conjunction of June 17, 2B.C. was an occultation of Jupiter by Venus, in which Venus covered over Jupiter, so that these planets would have merged in the sky. This extremely rare event has happened a couple other times in history, and is calculated to happen again, according to this page.
Anyway, this notion of the 2 B.C. series being the "Star of Bethlehem" was a new one on me. Interestingly, there is another popular theory of the Star that
is set in this very same time period. In between these Jupiter/Venus conjunctions of 2 B.C. was a very close triple conjunction of Jupiter with the star Regulus, and this separate, distinct event is already espoused by some as an interpretation of the Star of Bethlehem! All these theories appeal to astrology and astrological symbolism, as would be purportedly understood by Persian magi (Leo as the "Lion of Judah," Regulus being a "royal" star, Jupiter being a "kingly"
planet, etc.)
So it's interesting that just this past week, a new pop theory should emerge involving Venus and Jupiter, with conjunctions sandwiched between the aforementioned triple conjunction. A new interpretation has gone forth among the faithful, as some are drawing great significance with
Venus as "the bright morning star," another Biblical association with Jesus.
Whatever the case, whether any or all of these conjunctions would be deemed astrologically notable to a first century Persian magus, it certainly does not seem like a "mere coincidence" that multiple, historically-rare sky
events should occur so closely to the birth of the King of Kings. It seems like that ought to somehow mean something. Notwithstanding, I personally do not espouse any theories that entail a naturalistic explanation for the Star of Bethlehem.
We should note that the Gospel of Matthew is the
only historical source that mentions the Star of Bethlehem, and there simply is not much information in this passage. These are the only three verses in the Gospel that mention the Star:
Saying, Where is he that is born King of the Jews? for we have seen his star
in the east, and are come to worship him. - Mt 2:2
When they had heard the king, they departed; and, lo, the star, which they saw in the east, went before them, till it came and stood over where the young child was. When they saw the star,
they rejoiced with exceeding great joy. - Mt. 2:9-10
Normal stars (or planetary conjunctions for that matter) do not "go before" anyone, nor do they "stand" over precise locations. Real celestial objects can only be seen passing overhead at the zenith over a
certain latitude. If you have a sextant or another precise, modern navigational instrument, this might help lead you to the latitude of Bethlehem, but it won't help you find the precise location of a young child within that little town.
There is a depiction of the Star of Bethlehem in the opening scene of the 1959 movie Ben Hur that closely matches the Gospel description of the supernatural behavior of the Star of Bethlehem. This scene shows the "star" moving through the sky, "going before" the
wise men, and then "standing over" the place of the Christ child, shining down from on high to illuminate the precise location.
Normal celestial objects simply do not behave in a miraculous fashion like that. Stars (and conjunctions) rise, cross the meridian, and then set, just like the Sun. In my
opinion, we should not look at any natural phenomenon to explain the Star of Bethlehem. The devotees of the various popular theories have their own "talk-arounds" to sidestep the issue of the supernatural behavior of the Star of Bethlehem. But as for me and my house, I'm unpersuaded. These theories come and go, and any attempt to nail down an authoritative answer on the subject is shifting sand, in my
opinion. I'd encourage everyone to do their own study of this subject and be fully convinced in their own hearts.
The Extended Alignment of Jupiter and Venus
As mentioned in the last newsletter, the Venus/Jupiter conjunction of June 30, 2015 was indeed a rare event. The conjunction itself was extremely close, which is rare enough. Also, the conjunction was well-placed in the evening sky, not too close to the Sun, and high above the horizon during dusk
twilight. But the most rare part is the extended alignment of these planets that will be going on during July and August! Such an occurrence will not happen again in our lifetimes!
Before explaining the extended alignment and rarity thereof, let's first understand what's going on in the solar system, and the circumstances that produced this conjunction. Venus is an inferior planet, which means
that its orbit is inside the Earth's orbit, closer to the Sun. For this reason, Venus is always seen in the general direction of the Sun, as seen from the Earth, before sunrise or after sunset.
During the current season, Venus has had an eastern elongation, which means it is seen to the east of the Sun, or rather, visible in the evening sky after the sunset. An eastern elongation of Venus begins
with prograde motion, when it emerges from behind the Sun, and appears to move east in its orbit through the constellations. When prograde, Venus appears to emerge from the sunset, and draws higher in the evening sky as its elongation increases.
Venus reaches its maximum eastern elongation when it appears to be furthest from the Sun in the evening sky. This occurred on June 6, 2015. After its maximum, Venus appears to "hover" in the sky for a time,
after which it draws close to the Sun again. This is its retrograde motion, when Venus appears to be moving west through the sky, or dropping lower in sky toward the sunset. At some point, Venus vanishes into the sunset glow, after which it lines up invisibly between the Earth and the Sun at its inferior conjunction.
Meanwhile, Jupiter is a
superior planet, whose orbit is outside the orbit of the Earth. Jupiter moves rather slow through the constellations, especially compared to swift Venus. So Jupiter appears more or less stationary among the stars. However, the motion of the Earth is only visible in the sky as an apparent motion of the Sun, which at all times appears to be moving toward the east through the constellations.
But we can't really notice the Sun's motion per se. The Earth's motion results in a changing line of sight between the Sun and the background constellations. This makes each of the constellations appear to be shifting slowly toward the sunset as the seasons pass. In the current month of July, it appears that Leo is creeping
steadily toward the sunset as the days and weeks pass. But since Jupiter is near Leo, we see this planet steadily dropping toward the sunset, along with Leo. Jupiter will eventually disappear into the sunset, as the planet lines up behind the Sun, as seen from the Earth.
The combined effect of these planetary motions in 2015 meant that Venus was heading "upwards" away from the sunset at the same time as Jupiter was heading "downwards" toward the sunset. So Venus and Jupiter
"met in the middle" on June 30, the night of their conjunction. The changes in their positions are subtle from day to day, so these planets still appear closely aligned into early July.
Most of the time, when Jupiter and Venus have an evening conjunction, it's typical that Venus continues to go "upwards" for a time after the conjunction, while Jupiter continues going "downwards" toward the sunset. So these two planets usually go separate ways after the night of their conjunction. However, in 2015, Venus was just past its maximum, and was "hovering"
just as Jupiter was lining up with it. So now, in July, Venus will be dropping downwards toward the sunset at the same time as Jupiter!!!! Consequently, the planets will remain essentially aligned as they both sink into the glow of twilight, as they follow their own alignments with the Sun!!!
By July 11, Venus will have dipped down a bit in its orbit, while Jupiter and Leo also drop together a little closer to the
Sun.
As seen from a "God's eye view," out in space, the Earth and Venus are moving together in such a way that Venus appears to be in the same general direction as Jupiter. Thus, Venus and Jupiter remain in the same line of sight as the planets descend toward the sunset.
The thing to notice is how Venus and Jupiter and will be spreading apart sideways as they drop together into the sunset. At the time of conjunction, they were so close that you could cover over both of them with the tip of your finger, extended at arm's length. At this writing, they have pulled apart so that a finger can pass between these planets. As they continue, they will be more than three fingers apart.
While such a sight might not be as beautiful or awe-inspiring as the close conjunction itself, it is extremely rare for the motions of two planets to coincide so perfectly, as they drop into the sunset.
If you have a clear enough sky, try to notice that Venus is drawing closer to Regulus, as it pulls away from Jupiter. The scene will get more interesting when the waxing crescent Moon joins the planets on Saturday, July 18. But you'll want a very clear, flat horizon, free of trees and buildings, in order to see this low-riding lunar conjunction. The Moon will
still be in the scene the next night, Sunday, July 19.
After a series of evening conjunctions going back to wintertime, this will be the last lunar conjunction with Jupiter or Venus until the planets emerge from the Sun's glare in the morning, sometime in September. There will then be a season of morning conjunctions after that for all you earlybirds!
This particular close conjunction in 2015 represents the end of a century-long series of May/June conjunctions with Jupiter and Venus. Every 24 years, Jupiter and Venus would line up in this part of the sky, near Leo. Jupiter takes about 12 years to complete one circle of the constellations. Meanwhile, Venus has a cycle where five maximum elongations occur
every eight years. So every 24 years, Jupiter would line up with Venus when it has a maximum elongation near Leo. This is because two 12-year Jupiter cycles equals three 8-year Venus cycles, so that the cycle recurs just about every 24 years. But there is some "small change" between the cycles of Jupiter and Venus, causing a bit of drift over time.
This graphic below shows where Jupiter would have been in previous cycles on about July 30. In 2015, these planets lined
up in a conjunction on that date. But in 1991, they lined up earlier in the month, on June 16 (at which time, Mars joined them in a trio). Conjunctions also occurred on earlier dates in previous cycles, on June 8, 1967, May 31, 1943, and May 24, 1919. In each of those instances, Venus continued heading "upwards" while Jupiter continued dropping "downwards," so that the planets were only aligned on the day of conjunction. Only in this year, in 2015, were the
planets perfectly "balanced" so that Venus and Jupiter could drop downwards together.
But 2015 represents the end of this cycle of conjunctions. In 2039, 24 years from now, Venus will reach its maximum elongation before Jupiter arrives! So Venus will already be "dropping down" before lining up with Jupiter! The situation will be progressively worse in 2063 and more so in 2087.
In those instances, and for centuries to come, Jupiter in Leo will be further and further from Venus at the time of maximum elongation.
So for this reason, no one alive today will see Jupiter and Venus meeting together in June and July, and dropping into the sunset. What will happen instead
in 2039 is that Venus will have already begun its retrogradation, dropping down toward the sunset, while Jupiter is still far away. The planets will have an appulse, which is their closest approach, but there will not be a proper conjunction, as such. And the appulse will be wider in 2063 and still wider in 2087.
With astronomy, "the LORD giveth and the LORD taketh away." Though the 24 year cycle in Leo ending in 2015 won't recur anytime soon, there are other cycles of Venus and Jupiter, so these two meet up all the time. Venus will have another maximum eastern elongation in Aquarius on January 12, 2017, in Virgo on August 17, 2018, in Aries on March 24, 2020, and in Sagittarius on October 30, 2021.
These cycles will repeat every 8 years, and eventually Jupiter will be nearby Venus at one of these maximums, so that similar 24 year cycles can occur in these constellations. But all that is for another future newsletter! (Or perhaps another newsletter writer!)
All that being said, there is still more to come in 2015 with Jupiter and Venus! There will
be a very interesting morning series of conjunctions in October ,and this time including the Moon, Mercury and Mars! We hope to cover that at the time, but here's a little "sneak preview" of the conjunctions to come:
Oct 08: Moon and Venus
Oct 09: Moon and Mars and
Jupiter
Oct 11: Moon and Mercury
Oct 17: Mars and Jupiter
Oct 26: Venus and Jupiter
Nov 02: Venus and
Mars
Meantime, I'm taking the rest of the summer off from writing this newsletter. We'll be back in September to discuss the SPECTACULAR "Blood Moon" lunar eclipse that will favor the USA, and then we'll talk about the above conjunctions in October. So everyone have a nice remainder of the
summer!
Til
next time, God bless and clear skies,
- jay
The Ryan Family Cleveland, Ohio,
USA
When I consider thy heavens, the work of thy fingers, the moon and the stars, which thou hast ordained, what is man that thou art mindful of him? and the son of man, that thou visitest him? - Psalm 8:3-4, a Psalm of David
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